200 controls won't be a problem, I used the action in scenarios like this already.

However it's difficult to only show controls that have a value. Update document action basically defines placeholders in the word document, that can be filled out with values from workflow variables / columns and so on. As you usually want to have a label in the document and not only the value, the label will remain even if there is no value to save.

If thats not apropriate it might be better to have a look at the print to PDF Forms Enterprise feature. This will respect your form's rules that can hide controls without values.

I am now able to update a word document. But the problem i see is, in my content control there is a header, and content in paragraph. When i am updating the content, it only update the header but not all the content in the content control.

Where do you think i might have gone wrong while updating the content?